What Is Strategy?
Porter's short, canonical HBR article that argues strategy is about choosing to do things differently, not about doing the same things better — operational effectiveness is necessary but not strategic.
The piece's most useful distinction is between activities that improve operational effectiveness (convergent, winnable only on a treadmill) and activities that create a distinctive strategic position (fit between activities, hard to imitate).
For product direction, reading Porter's original is more useful than reading summaries of Porter — the argument is more specific than the summaries suggest and more applicable to actual strategy conversations.
Short, dense, canonical. Pair with Magretta for the book-length expansion and Rumelt for the operational critique.
Central argument
Porter argues that strategy is not about doing the same things better than competitors — that is operational effectiveness, which is necessary but not sufficient and ultimately leads to competitive convergence. True strategy means choosing a distinctive position: serving particular needs, particular customers, or using particular activities in ways that differ from rivals. The core mechanism is fit — the interlocking of mutually reinforcing activities that makes a strategic position coherent and, critically, hard to imitate because competitors cannot copy one activity without dismantling the whole system.
Critique
Porter's framework assumes relatively stable industry boundaries and activity systems, which made more sense in 1996 than in markets where platform dynamics, network effects, and rapid technological shifts can dissolve competitive positions faster than fit can be established or defended. The argument also treats imitation as the primary threat to strategy, but in digital markets the more common failure mode is irrelevance — being outpaced by a new activity system rather than copied within the existing one. This doesn't invalidate the framework but limits how directly it maps onto environments where the activity landscape itself is being redefined.
Why it matters for product
For a CPO, Porter's distinction between operational effectiveness and strategic positioning is a direct diagnostic for a recurring failure mode: product roadmaps that optimize existing flows — faster onboarding, better retention, tighter delivery cycles — without ever committing to a distinctive position on who the product serves and how. The concept of fit is particularly actionable in organizational design: if your product's activities are loosely coupled and independently defensible, you likely don't have a strategy, you have a feature portfolio. Porter's logic also provides a principled reason to say no — not because resources are scarce, but because adding capabilities inconsistent with the position degrades the fit that makes the position defensible.